When Syncope Strikes
BY WILLIAM TOWNSEND, OD
One of the most disturbing situations we encounter as healthcare providers is syncope or fainting. We recently saw a 22-year-old male who complained of pain and foreign body sensation that began after he was grinding metal. Slit lamp examination revealed a 0.5mm foreign body in the midperipheral right cornea. We advised the patient that we needed to remove the foreign body from his cornea. After we instilled a topical anesthetic, the patient collapsed. We immediately checked his pulse, evaluated his breathing and determined that his airway was open. After we placed the patient in a supine position and elevated his lower extremities, we placed a cool, damp towel on his forehead and continued to monitor his vital signs. He recovered and eventually underwent the procedure.
Why Syncope Happens
Syncope is defined as "a transient loss of consciousness with an inability to maintain postural tone that is followed by spontaneous recovery." It results from decreased cerebral perfusion, often due to hypotension. Brain tissue can't store energy, so reduced perfusion for greater than five seconds may cause syncope.
Syncope falls into two major categories. Cardiac syncope can be associated with cardiomyopathy, congestive heart failure, valvular insufficiency, obstruction, arrhythmias or conduction defects. Non-cardiac causes include vasovagal syncope, dehydration, autonomic dysfunction and psychiatric disease.
Vasovagal syncope is a biphasic reaction centered around the fight-or-flight reaction. It occurs when individuals experience a perceived or actual danger or threat, especially when it involves pain. During the initial phase lasting a few minutes, heart rate, cardiac output, blood pressure and total systemic resistance increase. During the second phase, a dramatic reversal occurs: Heart rate, blood pressure and peripheral resistance decrease rapidly. The resulting reduction in blood flow to the brain causes decreased perfusion, lightheadedness and eventually unconsciousness. Symptoms include nausea, sweating, clammy skin, skin pallor, dizziness and loss of extra-ocular muscle control. Patients may also lose the ability to gaze laterally.
Situational syncope dominates in eye care. It may occur after tonometry, contact lens application or procedures such as foreign body removal. Situational syncope isn't life threatening, but it can cause morbidity. The tendency to faint may arise from abnormal vagal tone and tends to be familial.
What to Do
Management of syncope begins with knowing the ABCs of life support. First establish that the airway is open, then make certain that the patient is breathing and finally, check for a pulse. Then check pupillary reflexes. Although it's extremely rare, vasovagal reactions may result in cessation of breathing, severe hypotension and death.
Because the real problem is lack of cerebral vascular flow, place the patient in the Trendelenburg position with the torso higher than the head. Your exam chair may tilt back far enough to place the patient in this position, or you can position him on the floor in a supine position and elevate his feet higher than his head. Ammonia spirits (smelling salts) help re-establish consciousness. Placing a cool, moistened towel on the patient's forehead is also helpful. Rarely, a patient may totally lose pulse and blood pressure during a vasovagal reaction. In these extreme instances, 0.4mg of atropine administered subcutaneously can save the patient's life.
When patients recover consciousness, arrange for a friend or family member to drive them home. Record the episode as well as your treatment and include in your charting any measures you address such as transportation and monitoring. Syncope is an uncommon, but very real condition that you should be prepared to manage in practice.
Dr. Townsend is in private practice in Canyon, Texas, and is a consultant at the Amarillo VA Medical Center. E-mail him at email@example.com.